1. Field of the Invention
The present invention relates to an MRAM (Magnetic Random Access Memory) which forms a memory cell by using an MTJ (Magnetic Tunnel Junction) element which stores “1” or “0” data by the TMR (Tunneling MagnetoResistive) effect, and a method of manufacturing the same.
2. Description of the Related Art
A number of memories which store information by new principles have been proposed in recent years. One of them is a magnetic random access memory using the tunneling magnetoresistive effect.
The magnetic random access memory stores “1” or “0” data by using an MTJ (Magnetic Tunnel Junction) element. This MTJ element includes a fixed layer with fixed magnetization, a recording layer whose magnetization is inverted, and a tunnel insulating film sandwiched between the fixed layer and the recording layer. The “1” or “0” data stored in the MTJ element is determined on the basis of whether the magnetization directions of the fixed layer and recording layer are parallel or anti-parallel.
In the conventional magnetic random access memory, however, the characteristics of the magnetic material in the junction isolation sidewall and the tunnel insulating film of the MTJ element degrade due to outgas (e.g., H2O) from the interlayer film buried around the MTJ element. For this reason, the magnetic characteristics of the MTJ element degrade.
Prior art related to the present invention is as follows:
[Patent Reference 1] Jpn. Pat. Appln. KOKAI Publication No. 2003-243630
[Patent Reference 2] Jpn. Pat. Appln. KOKAI Publication No. 2003-299726